It has been conventional with automatic rhythm-accompaniment apparatus used in electronic musical instruments that, when a player depresses several keys, for example, with the left hand, rhythm tones or rhythm-base tones corresponding to chords of the keys depressed are obtained by rhythm pulses generated in an automatic rhythm pulse generator. In such case, the player must play a melody with his right hand. As a result, this operation is very difficult for a beginner who must effect key depression with his left hand and, at the same time, obtain a melody with his right hand.